Conventional wideband switching networks have been designed to steer signals through appropriate narrower band filters. Each filter is accessed individually according to the switch settings. As the number of filters increases, the switching losses increase correspondingly.
Conventional diplexer structures are not generally considered to have acceptable performance over a wide frequency band (greater than one decade in frequency). Some cascaded diplexers can allow realizable concurrent frequency selective filtering over 4 decades in frequency.
Networks that combine bandpass filters into a broader band common port exist. One example is a log periodic antenna that combines multiple band pass antenna elements into a broader contiguous frequency band in parallel along a transmission line. Antenna multicouplers typically use several bandpass filters in parallel to combine several radios to a single antenna. The parallel arrangement means the undesired resonances are not decoupled from the output.
The novel filter network arrangement disclosed, allows multiple filters to be accessed concurrently. Additionally, switching may be embedded inside the filter network, avoiding the cascaded switching losses.